A native band downstream from what may become the biggest mine in Canada says it is worried about the long-term threat that pollution could pose to the Nass and Bell-Irving Rivers in northwest B.C.

"The mine's life span is for 50 years and they are estimating that mine will be required to treat [waste water] for well over 200 years. And who's going to be responsible for that?" Glen Williams, Hereditary Chief of the Gitanyow First Nation said Wednesday.

The Kerr-Sulphurets-Mitchell (KSM) mine, which Seabridge Gold Inc. is proposing to build high in the mountains 65 kilometres northwest of Smithers, would use tailings ponds and a water treatment plant to handle pollution generated by two billion tons of waste rock.

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Brent Murphy, vice-president of environmental affairs for the Toronto-based resource explorations company, said, "Protection of the environment has been a key guiding principle in the design of the project, and we've worked very hard to ensure that there's no impact downstream of the facility."

An environmental impact statement filed by the company says discharges from the copper-gold mine will have no significant impact on fish and the aquatic habitat overall.

Mr. Murphy said four other First Nations in the region have expressed confidence in the plans, and the Nisga'a Nation last August signed an agreement in principle with Seabridge. In a press release at that time, Nisga'a president Mitchell Stevens praised the company for being "very responsive to our concerns around the environmental and social impacts of the project."

Mr. Murphy said meetings were taking place with Gitanyow leaders Wednesday and "we're hopeful we'll eventually address [their] concerns."

Mr. Williams said he also hopes talks can resolve the issue, but for now he remains worried. "We are extremely concerned about the project plan to establish the tailing management facility in the headwaters of the Bell-Irving River and transport billions of tons of potential acid generating rock … into the pristine headwaters of the Nass River," he said in a letter to the Canadian Environmental Assessment Agency this week. "We are extremely mindful that if this project is approved, that threat will likely be there forever."

A Gitanyow study of the mine proposal concludes it could release water polluted with heavy metals that "may be toxic to fish at sub-lethal levels" far downstream of the site.

Mr. Williams said the band is not saying no to the KSM mine, which is currently undergoing a joint federal-provincial environmental review, but the band wants greater assurances. "We need certainty," Mr. Williams said. "There are toxins that could spill over into the Nass and affect our food supply."

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The company describes the mine as "one of the largest undeveloped gold projects in the world" with probable reserves of 38 million ounces of gold and nearly 10 billion pounds of copper.

Mr. Williams said one of his concerns is that the province is rushing the evaluation process for political reasons. Last year, the B.C. government promised that within two years eight new mines would be opened in B.C. and nine existing mines would be expanded. Mr. Williams said the "massive scale" of the KSM project, which is expected to create 6,500 full-time jobs, makes it a top government priority.

"They are on a political agenda to fast-track these [mining] projects and get them through the system as quickly as possible," he said.

The company is hoping to get clearance to start construction by the middle of this year.

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